Cluster plug



June 9 5 1,540,174 c. s. MALLETT CLUSTER PLUG Nov. 26, 1-921 ,fzz vezztor, C. 5. MA 11.227.

ter Plugs,

Patented June 2, 1925.

UNITED STATES PATEN 1* OFFICE.)

CHARLES STANLEY MALLETT, 0F TORONTO, ONTARIO, CANADA.

CLUSTER PLUG.

Application filed November 26, 1921. Serial No. 517,971.

To all whom it may concern:

Be it known that I, CHARLES STANLEY ,MALLEPI, a subject of the King of Great object is to construct a cluster plug in which the sectional threaded metal contact pieces replacing the lamp screw shells will form a perfect contact with the lamp and which moreover, may be constructed very cheaply.

My invention consists of a cluster plug constructed and arranged substantially as hereinafter more particularly described and illustrated in the accompanying drawing in which: 7

Fig. 1 represents a perspective view of a cluster plug constructed according to my invention.

Fig. 2 is a cross sectional view through the cover thereof, showing the base in elevation and showing the disposition of the sectional contact pieces in said cover.

Fig. 3 is a similar section of the cover to that shown in Figure 2, with the sectional contact pieces removed, and

Fig 4 is an elevational detail of the contact pieces used in a double cluster plug,

showing the means of connecting them to the main screw plug shell.

Fig. 5-is a cross sectional view on the line 5-5, Fi re 4.

Like 0 aracters of reference indicate corresponding parts in the different views.

1 is the base of the plug constructed of suitable material such as porcelain and provided with an upwardly extending shank 2 carrying the main screw plug shell 3. 4; are inwardly extending teats formed on the top of the main screw plug shell 3 and adapted to be inserted into in entures 5 in the shank 2. 6 is an annular depending portionformed on the lower face of the base 1 and provided with the depending wedge- .tact pieces are adapted to be shaped boss 7 having its two side wall'siincllned oppositely at suitable angles.

8 is a hollow cover constructed of insulatr.

ing material such as porcelain and provided with oppositely inclined annular orifices;;'9.

10 1s an annular shoulder formed in the open top ofthe' cover 8 to receive the depending portion 6 of the base. 11 is a strip of metal, the ends of which are oppositely inclined, said strip of metalbeing attached centrally of the bottom. of the boss 7 .by means of the vertical, screw 12 which ,extends u through the tion 6, ase 1 and shank 2 to the top of the latter and also holds in place the contact washer 13.

, 14 are'the opposed sectional threaded con-.

tact pieces preferably stamped of a single piece of metal, said contact pieces inserted into channels 15 in the orifices 9. 16 are suitably spaced longitudinal slots through 1e contact pieces in order that the portion boss 7, depending porof the material therebetween may be raised to constitute aspring and make a more perfect contact with the lamp base. The outer ends 17 of the contact pieces are flared tov facilitate the entry of lamp into the fitting. suitably secured to the necting the two contact pieces together, said metal strip extending up through thcbase 1,

the screw base of the 18 is a metal strip yoke-piece 19 ,oon-

shank 2 and suitably secured to one of the teats at of the main screw shell. v In inserting the contact pieces 14 into the grooves 15 it will be understood that the side edges of such contact-pieces are turned to constitute flanges, the outer surfaces of which engage the side shoulders ,or. walls-:20 of the channel 15 and their free edgesengage the base of the channel in proximity.

to the shoulders 20. Consequently such'ico'nr sprung into such channel.

From the above description it will be seen that I have devisedjasimple and effective fitting thatwill replace theordinary lamp screw shells and which canbe manufactored at an exceedingly low cost. Owing to the spring of the contact pieces and in addition the central portion thereof being raised to constitute a spring, the contact with1 the screw lampbase will be exceedingly goo v j Although I have described and illustrated the contact pieces as applied to cluster plugs it is to be understood that a single contact piece could be used with any suitable lamp screw base receiving socket provided the same beconstructed of lnsulatmg materlal or has an insert of insulating material in resilient material sprung into slots in the orifices and constituting resilient contacts with the bases of the lamps inserted into such orifices. Y

2. In cluster plugs, the combination with a cover having lamp base receiving orifices, of segmental conducting contact pieces of resilient material sprung into slots in the orifices and constituting resilient contacts with the bases of the lamps -inserted into such orifices, said contact pieces ribbed transversely, suchv ribs itched at the same pitch as the threads oftiie lamp bases.

3. In cluster plugs, the combination with a cover having lamp base receiving orifices, of segmental conducting contact pieces of resilient material sprung into slots in the orifices. and constituting resilient contacts with the bases of the lamps inserted into such orifices, said contact pieces. ribbed transversely, such ribs pitched at the same pitch as the threads of the lamp bases, and resilient raised portions on said contact pieces constituted by double slotting the same longitudinally and embossing the portions lying between said slots.

CHARLES STANLEY MALLETT. 

